A microtomographic analysis was a very thorough molecular analysis.
When the dilithium chamber hatch aboard the USS Enterprise-D exploded in 2367, Geordi La Forge and Data made a microtomographic analysis of the dilithium chamber and the hatch mounting. They detected sub-micron fractures in the metal casing, a breakdown in the atomic cohesive structure. This meant that neutron fatigue caused the explosion, not sabotage by the Klingon exobiologist J'Dan, as was originally suspected. (TNG: "The Drumhead")